The Best Macronutrient (Macro) Calculator to Lose Weight and Build Muscle

Use our free macro calculator below to learn how much of each macronutrient you should eat daily to achieve your goals.

For your personalized macronutrient ratios, simply enter your sex, height, weight, age, and physical activity level, and our macronutrient calculator will do the rest.

What Are Macronutrients (“Macros”)?

A macronutrient (“macro”) is a nutrient that your body needs in large amounts to survive. The main macronutrients are carbs, protein, and fat. 

To better understand the roles of carbs, protein, and fat in shaping your flexible dieting meal plans, let’s look at each separately.

Carbohydrates

There are three main types of carbohydrates: sugar, starch, and fiber. 

The body breaks down sugar and starch into glucose, the primary energy source for the brain, central nervous system, and red blood cells, while fiber helps you stay satiated and maintain good digestive health. 

Carbs contain four calories per gram, and you can find them in large amounts in foods such as vegetables, fruits, grains, tubers, and cereals.

Protein

The primary reason to eat protein is to provide your body with enough essential amino acids to build and repair cells. 

Protein contains four calories per gram, and you can find it in large amounts in foods such as lean meat, fish, Greek or Icelandic yogurt, cheese, eggs, and pulses.

Fat

Dietary fat serves multiple crucial roles in the body, including optimizing your immune system, building cells (especially nerve cells), and providing energy. 

Fat contains the most calories of any macronutrient, providing nine calories per gram. High-fat foods include oils, nuts and nut butters, seeds, and fatty meat, fish, and dairy products.

Daily Calorie Needs

Your sex, age, height, weight, and level of physical activity all influence your daily calorie requirements.

For example, a tall, young, active man with a muscular build will need more calories than a petite, overweight older woman with a sedentary lifestyle.

As per the U.S. Department of Agriculture’s 2020–2025 Dietary Guidelines, an average man should aim to consume 2,000-to-3,000 calories daily, while a woman typically requires 1,600-to-2,400 calories per day.

While these estimates serve as a starting point, you’ll want to track your calorie intake more closely to build muscle mass, lose body fat, or maintain your physique effectively.

That’s why the Legion Macro Calculator provides in-depth data about calories and macros, so you know exactly how many calories to eat each day, whether you want to eat in a calorie deficit, surplus, or at maintenance.

Why Should I Track Macros?

While counting the number of calories you consume is paramount for helping you lose, maintain, or gain weight, it’s equally crucial to count macros. 

Doing so helps you optimize your body composition and boost your overall health, particularly when dieting to lose weight. 

For example, dieters commonly undereat protein. Typically, this leads to muscle loss and means they develop a “skinny-fat” appearance instead of the lean, defined body they’re striving for.

Likewise, many dieters severely limit their dietary fat intake. While lowering your fat intake can make hitting a reduced calorie target more straightforward, eating too little can compromise your health. 

In other words, counting macros allows you to fully customize your meal plan, ensuring you eat the right balance of macronutrients to enhance your health and body composition and achieve your goals.

Unlike more rigid dieting strategies, macro tracking allows you to embrace a “flexible dieting” approach to nutrition. Flexible dieting allows you to choose foods that suit your tastes and enjoy occasional indulgences, something that can make long-term adherence easier. 

As with any dieting strategy, counting macros has its drawbacks.

For beginners, understanding the concept of macros and how to calculate them can be daunting. The process also requires a commitment to weighing and portioning food meticulously, which some find inconvenient.

Despite these potential hurdles, however, the benefits of tracking macros outstrip the downsides for most people, which is why studies typically show that flexible dieters have an easier time losing weight and keeping it off than those who use a more rigid approach.

How Do I Calculate the Macros in My Food?

If your food is packaged, simply refer to the nutritional information on the label.

Ideally, most of your meals should be prepared and cooked at home using minimally processed foods. For nutritional information about these foods, the following websites are reliable resources:

• CalorieKing
• SELF Nutrition Data
• The USDA Food Composition Databases

Finding information on foods on these sites is straightforward:

1. Search for the food. If the exact brand or product is listed, use that.
2. If the exact brand or product isn’t listed but an “average for all brands” is, use that.
3. If neither the exact brand or product nor an average for all brands is listed, check multiple entries for the type of item to get an idea of the range. Choose numbers that are in the middle.

For example, if you want to add a cup of Uncle Ben’s rice to your meal plan, you can find this exact food listed on CalorieKing. If it’s a cup of bulk rice, though, you can search for the type of rice it is and choose the average for all brands.

It’s critical that your food calculations are accurate. That’s why you want to weigh everything you eat before cooking to determine its calories and macros, and when preparing multiple servings, weigh again after cooking to determine portion sizes.

Let’s say you’re preparing a pound of chicken for four meals. Start by weighing out 454 grams of raw chicken, cook it, and then divide it into four roughly equal portions. Remember, the portions won’t be exactly 454 divided by 4 because cooked chicken weighs less than raw due to moisture loss.

For meals that don’t require cooking, simply weigh them before you eat.

Remember that small measurement inaccuracies can significantly skew your numbers when measuring by volume (using cups and spoons) instead of weight (ounces and grams).

For example, a heaping tablespoon of peanut butter doesn’t look much different from a properly measured tablespoon. Still, it could add 50-to-100 calories to the meal.

You must also include absolutely everything you’re going to eat in your meal plan. That includes vegetables, fruits, condiments, dabs of oil and butter, and every other morsel of food you eat daily.

Macronutrients in Common Diet Foods

Here’s the calorie and macro content of some common diet staples: